SUM(1)SUM(1)
NAME
sum, md5sum, sha1sum - sum and count blocks in a file
SYNOPSIS
sum [ -5r ] [ file ... ]
md5sum [ file ... ]
sha1sum [ -2 bits ] [ file ... ]
DESCRIPTION
By default, sum calculates and prints a 32-bit hexadecimal
checksum, a byte count, and the name of each file. The
checksum is also a function of the input length. If no
files are given, the standard input is summed. Other sum-
ming algorithms are available. The options are
-r Sum with the algorithm of System V's sum -r and print
the length (in 1K blocks) of the input.
-5 Sum with System V's default algorithm and print the
length (in 512-byte blocks) of the input.
Sum is typically used to look for bad spots, to validate a
file communicated over some transmission line or as a quick
way to determine if two files on different machines might be
the same.
Md5sum computes the 32 hex digit RSA Data Security, Inc. MD5
Message-Digest Algorithm described in RFC1321.
Sha1sum computes the 40 hex digit National Institute of
Standards and Technology (NIST) SHA1 secure hash algorithm
described in FIPS PUB 180-1, by default. Given the `2'
option, it instead computes the bits-bit NIST SHA2 secure
hash algorithm described in FIPS PUB 180-2 and prints the
hash in hex. Currently supported values of bits are 224,
256, 384, and 512.
SOURCE
/sys/src/cmd/sum.c
/sys/src/cmd/md5sum.c
/sys/src/cmd/sha1sum.c
SEE ALSO
cmp(1), wc(1), sechash(2)